Math FFT
126 TDS1000/2000-Series Digital Oscilloscope User Manual
Measuring an FFT Spectrum Using Cursors
You can take two measurements on FFT spectrums: magnitude
(in dB) and frequency (in Hz). Magnitude is refere nced to 0 dB,
where 0 dB equals 1 VRMS. You can use the cursors to take
measurements at any zoomfactor.
Push CURSOR "Source and select Math. Push the Type option
button to select between Magnitude and Frequency. Use the Vertical
Position knobs to move cursors 1 and 2.
Use horizontal cursors to measure magnitude and vertical cursors to
measure frequency. The options display the delta between the two
cursors, the value at cursor 1 position, and the value at cursor 2
position. Delta is the absolute value of cursor 1 minus cursor 2.
Magnitude cursors Frequency cursors
You can also take a frequency measurement. To do so, turn the
Horizontal Positionknob to position a frequency component on the
center graticule line and read the frequency at the top right of the
display.